1. Field of the Invention
The present invention relates to brush rolls for brushing metal plates, and more particularly to brush rolls for use in brushing, i.e. polishing, grinding, cleaning or otherwise treating steel plates or sheets, thin stainless steel sheets, other metal strips or the like in the cold rolling process.
2. Description of the Prior Art
Brush rolls which are well known for such a brushing treatment comprises a multiplicity of annular brush disks each in the form of a single piece and bristles of synthetic material attached to the outer peripheral edge of the disk. The brush disks are fitted to a shaft and drivingly connected to the shaft. Since the brush disk of the prior art is a completely annular piece, the disk can not be fitted to the shaft unless it is passed over the shaft end. For this fitting method, the shaft must be supported only at its one end with the other end thereof left unsupported as a free end. Accordingly, the shaft is usually positioned vertically when the brush disks are to be fitted thereto. The shaft of this type of brush roll is generally as long as about 3 m. Difficulties are encountered in fitting the disks from shaft free end with the long shaft positioned vertically. In fact, the worker must move up and down repeatedly on a lift when fitting the disks to the shaft. This work lacks safety.
The disk of the prior art is a thin metal plate so as to achieve the greatest possible cost reduction and assure ease of machining. Holes are formed in the thin disk at a spacing along its outer periphery, a bundle of bristles is passed through each hole and then bent outward in a U-shape, and the bristles are bound together at the bent portion. Accordingly, unless the multiplicity of brush disks fitted to the shaft are fully compressed by a press, the disks can not be assembled compactly as required longitudinally of the shaft. A large-sized press of great output is needed to effect the desired compression filfilling the requirement. Such a press is generally as great as about 4 m in height and about 50 to about 100 tons in output.
The assembly of disks is locked to the shaft by a snap ring and held compressed.
The brush roll usually has a length greater than the width of the metal plate to be brushed. Accordingly, the wear of the bristles is not uniform longitudinally of the brush roll. If the bristles are worn unevenly, the uneven wear must be remedied. For this purpose, it is practice with the prior art to trim the bristle assembly of the brush roll, or to replace the brush disks with worn bristles by new ones. In the former case, the bristles must be trimmed at a repair factory by a skilled worker. The replacement of brush disks involves the necessity of gradually releasing the brush disks from compression; if otherwise some disks will flounce to incur a hazard. Thus, neither of the prior-art methods are easy to practice at the site of brushing operation.